/*
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2 of the License, or
 *    (at your option) any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/*
 *    Copy.java
 *    Copyright (C) 1999 University of Waikato, Hamilton, New Zealand
 *
 */

package weka.filters.unsupervised.attribute;

import weka.core.Attribute;
import weka.core.Capabilities;
import weka.core.Instance;
import weka.core.Instances;
import weka.core.Option;
import weka.core.OptionHandler;
import weka.core.Range;
import weka.core.RevisionUtils;
import weka.core.SparseInstance;
import weka.core.Utils;
import weka.core.Capabilities.Capability;
import weka.filters.Filter;
import weka.filters.StreamableFilter;
import weka.filters.UnsupervisedFilter;

import java.util.Enumeration;
import java.util.Vector;

/**
 * <!-- globalinfo-start --> An instance filter that copies a range of
 * attributes in the dataset. This is used in conjunction with other filters
 * that overwrite attribute values during the course of their operation -- this
 * filter allows the original attributes to be kept as well as the new
 * attributes.
 * <p/>
 * <!-- globalinfo-end -->
 * 
 * <!-- options-start --> Valid options are:
 * <p/>
 * 
 * <pre>
 * -R &lt;index1,index2-index4,...&gt;
 *  Specify list of columns to copy. First and last are valid
 *  indexes. (default none)
 * </pre>
 * 
 * <pre>
 * -V
 *  Invert matching sense (i.e. copy all non-specified columns)
 * </pre>
 * 
 * <!-- options-end -->
 * 
 * @author Len Trigg (trigg@cs.waikato.ac.nz)
 * @version $Revision: 6996 $
 */
public class Copy extends Filter implements UnsupervisedFilter,
		StreamableFilter, OptionHandler {

	/** for serialization */
	static final long serialVersionUID = -8543707493627441566L;

	/** Stores which columns to copy */
	protected Range m_CopyCols = new Range();

	/**
	 * Stores the indexes of the selected attributes in order, once the dataset
	 * is seen
	 */
	protected int[] m_SelectedAttributes;

	/**
	 * Returns an enumeration describing the available options.
	 * 
	 * @return an enumeration of all the available options.
	 */
	public Enumeration listOptions() {

		Vector newVector = new Vector(2);

		newVector.addElement(new Option(
				"\tSpecify list of columns to copy. First and last are valid\n"
						+ "\tindexes. (default none)", "R", 1,
				"-R <index1,index2-index4,...>"));
		newVector
				.addElement(new Option(
						"\tInvert matching sense (i.e. copy all non-specified columns)",
						"V", 0, "-V"));

		return newVector.elements();
	}

	/**
	 * Parses a given list of options.
	 * <p/>
	 * 
	 * <!-- options-start --> Valid options are:
	 * <p/>
	 * 
	 * <pre>
	 * -R &lt;index1,index2-index4,...&gt;
	 *  Specify list of columns to copy. First and last are valid
	 *  indexes. (default none)
	 * </pre>
	 * 
	 * <pre>
	 * -V
	 *  Invert matching sense (i.e. copy all non-specified columns)
	 * </pre>
	 * 
	 * <!-- options-end -->
	 * 
	 * @param options
	 *            the list of options as an array of strings
	 * @throws Exception
	 *             if an option is not supported
	 */
	public void setOptions(String[] options) throws Exception {

		String copyList = Utils.getOption('R', options);
		if (copyList.length() != 0) {
			setAttributeIndices(copyList);
		}
		setInvertSelection(Utils.getFlag('V', options));

		if (getInputFormat() != null) {
			setInputFormat(getInputFormat());
		}
	}

	/**
	 * Gets the current settings of the filter.
	 * 
	 * @return an array of strings suitable for passing to setOptions
	 */
	public String[] getOptions() {

		String[] options = new String[3];
		int current = 0;

		if (getInvertSelection()) {
			options[current++] = "-V";
		}
		if (!getAttributeIndices().equals("")) {
			options[current++] = "-R";
			options[current++] = getAttributeIndices();
		}

		while (current < options.length) {
			options[current++] = "";
		}
		return options;
	}

	/**
	 * Returns the Capabilities of this filter.
	 * 
	 * @return the capabilities of this object
	 * @see Capabilities
	 */
	public Capabilities getCapabilities() {
		Capabilities result = super.getCapabilities();
		result.disableAll();

		// attributes
		result.enableAllAttributes();
		result.enable(Capability.MISSING_VALUES);

		// class
		result.enableAllClasses();
		result.enable(Capability.MISSING_CLASS_VALUES);
		result.enable(Capability.NO_CLASS);

		return result;
	}

	/**
	 * Sets the format of the input instances.
	 * 
	 * @param instanceInfo
	 *            an Instances object containing the input instance structure
	 *            (any instances contained in the object are ignored - only the
	 *            structure is required).
	 * @return true if the outputFormat may be collected immediately
	 * @throws Exception
	 *             if a problem occurs setting the input format
	 */
	public boolean setInputFormat(Instances instanceInfo) throws Exception {

		super.setInputFormat(instanceInfo);

		m_CopyCols.setUpper(instanceInfo.numAttributes() - 1);

		// Create the output buffer
		Instances outputFormat = new Instances(instanceInfo, 0);
		m_SelectedAttributes = m_CopyCols.getSelection();
		for (int i = 0; i < m_SelectedAttributes.length; i++) {
			int current = m_SelectedAttributes[i];
			// Create a copy of the attribute with a different name
			Attribute origAttribute = instanceInfo.attribute(current);
			outputFormat.insertAttributeAt(
					(Attribute) origAttribute.copy("Copy of "
							+ origAttribute.name()),
					outputFormat.numAttributes());
		}

		// adapt locators
		int[] newIndices = new int[instanceInfo.numAttributes()
				+ m_SelectedAttributes.length];
		for (int i = 0; i < instanceInfo.numAttributes(); i++)
			newIndices[i] = i;
		for (int i = 0; i < m_SelectedAttributes.length; i++)
			newIndices[instanceInfo.numAttributes() + i] = m_SelectedAttributes[i];
		initInputLocators(instanceInfo, newIndices);

		setOutputFormat(outputFormat);

		return true;
	}

	/**
	 * Input an instance for filtering. Ordinarily the instance is processed and
	 * made available for output immediately. Some filters require all instances
	 * be read before producing output.
	 * 
	 * @param instance
	 *            the input instance
	 * @return true if the filtered instance may now be collected with output().
	 * @throws IllegalStateException
	 *             if no input format has been defined.
	 */
	public boolean input(Instance instance) {

		if (getInputFormat() == null) {
			throw new IllegalStateException("No input instance format defined");
		}
		if (m_NewBatch) {
			resetQueue();
			m_NewBatch = false;
		}

		double[] vals = new double[outputFormatPeek().numAttributes()];
		for (int i = 0; i < getInputFormat().numAttributes(); i++) {
			vals[i] = instance.value(i);
		}
		int j = getInputFormat().numAttributes();
		for (int i = 0; i < m_SelectedAttributes.length; i++) {
			int current = m_SelectedAttributes[i];
			vals[i + j] = instance.value(current);
		}
		Instance inst = null;
		if (instance instanceof SparseInstance) {
			inst = new SparseInstance(instance.weight(), vals);
		} else {
			inst = new Instance(instance.weight(), vals);
		}

		inst.setDataset(getOutputFormat());
		copyValues(inst, false, instance.dataset(), getOutputFormat());
		inst.setDataset(getOutputFormat());
		push(inst);
		return true;
	}

	/**
	 * Returns a string describing this filter
	 * 
	 * @return a description of the filter suitable for displaying in the
	 *         explorer/experimenter gui
	 */
	public String globalInfo() {

		return "An instance filter that copies a range of attributes in the"
				+ " dataset. This is used in conjunction with other filters that"
				+ " overwrite attribute values during the course of their operation --"
				+ " this filter allows the original attributes to be kept as well"
				+ " as the new attributes.";
	}

	/**
	 * Returns the tip text for this property
	 * 
	 * @return tip text for this property suitable for displaying in the
	 *         explorer/experimenter gui
	 */
	public String invertSelectionTipText() {
		return "Sets copy selected vs unselected action."
				+ " If set to false, only the specified attributes will be copied;"
				+ " If set to true, non-specified attributes will be copied.";
	}

	/**
	 * Get whether the supplied columns are to be removed or kept
	 * 
	 * @return true if the supplied columns will be kept
	 */
	public boolean getInvertSelection() {

		return m_CopyCols.getInvert();
	}

	/**
	 * Set whether selected columns should be removed or kept. If true the
	 * selected columns are kept and unselected columns are copied. If false
	 * selected columns are copied and unselected columns are kept. <br>
	 * Note: use this method before you call
	 * <code>setInputFormat(Instances)</code>, since the output format is
	 * determined in that method.
	 * 
	 * @param invert
	 *            the new invert setting
	 */
	public void setInvertSelection(boolean invert) {

		m_CopyCols.setInvert(invert);
	}

	/**
	 * Get the current range selection
	 * 
	 * @return a string containing a comma separated list of ranges
	 */
	public String getAttributeIndices() {

		return m_CopyCols.getRanges();
	}

	/**
	 * Returns the tip text for this property
	 * 
	 * @return tip text for this property suitable for displaying in the
	 *         explorer/experimenter gui
	 */
	public String attributeIndicesTipText() {
		return "Specify range of attributes to act on."
				+ " This is a comma separated list of attribute indices, with"
				+ " \"first\" and \"last\" valid values. Specify an inclusive"
				+ " range with \"-\". E.g: \"first-3,5,6-10,last\".";
	}

	/**
	 * Set which attributes are to be copied (or kept if invert is true)
	 * 
	 * @param rangeList
	 *            a string representing the list of attributes. Since the string
	 *            will typically come from a user, attributes are indexed from
	 *            1. <br>
	 *            eg: first-3,5,6-last<br>
	 *            Note: use this method before you call
	 *            <code>setInputFormat(Instances)</code>, since the output
	 *            format is determined in that method.
	 * @throws Exception
	 *             if an invalid range list is supplied
	 */
	public void setAttributeIndices(String rangeList) throws Exception {

		m_CopyCols.setRanges(rangeList);
	}

	/**
	 * Set which attributes are to be copied (or kept if invert is true)
	 * 
	 * @param attributes
	 *            an array containing indexes of attributes to select. Since the
	 *            array will typically come from a program, attributes are
	 *            indexed from 0.<br>
	 *            Note: use this method before you call
	 *            <code>setInputFormat(Instances)</code>, since the output
	 *            format is determined in that method.
	 * @throws Exception
	 *             if an invalid set of ranges is supplied
	 */
	public void setAttributeIndicesArray(int[] attributes) throws Exception {

		setAttributeIndices(Range.indicesToRangeList(attributes));
	}

	/**
	 * Returns the revision string.
	 * 
	 * @return the revision
	 */
	public String getRevision() {
		return RevisionUtils.extract("$Revision: 6996 $");
	}

	/**
	 * Main method for testing this class.
	 * 
	 * @param argv
	 *            should contain arguments to the filter: use -h for help
	 */
	public static void main(String[] argv) {
		runFilter(new Copy(), argv);
	}
}
